This invention relates to a vehicle door lock having improved anti-theft features. In particular, this invention relates to a vehicle door lock having a shield for protecting the lock from being unlocked by means other than a key and a drop-off linkage between the key cylinder and the connecting rod.
Vehicle door latch systems are well known in the art. Typically, a vehicle door will have a latch for engaging and cinching onto a striker. The door will have an inside handle and an outside handle for releasing the latch and opening the door. Additionally, the door will have a lock for preventing the door from being opened by either the inside handle or the outside handle or both. For selected doors, the door is provided with a key cylinder for locking and unlocking the doors.
Optionally, vehicles can be provided with a power lock and unlock option. Each door latch is provided with an electric actuator for locking and unlocking the door latches. The actuators are electrically connected to a common station for effecting selected and ganged operation of the locks. The common station is now usually provided with a receiver which responds to a transmitter for remotely locking and unlocking the doors.
Additionally, rear doors are commonly provided with a lever for disabling the inside door handle for child proofing the vehicle.
Notwithstanding the ability to lock or disable the doors of the vehicle, the vehicle is still susceptible to theft by the use of a tool known as a xe2x80x9cslim-jimxe2x80x9d. The xe2x80x9cslim-jimxe2x80x9d tool is inserted between the window and the window seal to manipulate the connecting rods between the locking lever or the release handle and the door latch. The xe2x80x9cslim-jimxe2x80x9d tool will either unlock or open the door allowing the thief access to the vehicle, usually in less than 30 seconds.
The disadvantages of the prior art may be overcome by providing a vehicle door latch with a shield extending between the latch and a key cylinder and providing a drop-off linkage between the key cylinder and the connecting rod such that the shield protects against direct manipulation and the drop-off linkage protects against key cylinder tampering.
According to one aspect of the invention, there is provided a vehicle door lock assembly which includes a latch for mounting on a vehicle door. The latch has at least one release lever for effecting releasing of the latch and at least one locking lever for locking the latch, disabling the release lever, and unlocking the latch, enabling the release lever. A compound linkage operatively engages the locking lever. A lock cylinder has a spindle which engages the linkage. The spindle rotates in response to keyed rotation of a matched key being received by the lock cylinder which drives the linkage to effect movement of the locking lever. The spindle is axially slidable to disengage the spindle from the linkage. A hollow shield shrouds the locking lever, linkage and the engagement between the linkage and the spindle, preventing access thereto. If the spindle is removed, the linkage will pivot away preventing manipulation thereof.